The spout is vertical, slender and up to 9 m in height.īlue whales produce loud and deep sounds that are said to be ‘the most powerful sustained utterances known from whales or any other living source’. While breathing, the whale surfaces horizontally so that the blowhole and much of the back appear at the same time. Apparently they do not feed at all in the warmer waters. After the four months of the krill season in the polar region, the Blues move to the tropics. A large Blue Whale can consume four to eight tons of krill a day. Its width is only sufficient to allow the passage of krill that are about 5 cm long. The oesophagus of the Blue Whale is quite narrow. More krill has become available to other species. In the Southern Ocean the killing of Blue Whales and Fin Whales Balaenoptera physalus has led to a great increase in the krill population. As a result of intense hunting, the ecological balance in areas where whales were once common has been upset. There may be no more than a few hundred Blue Whales left in the southern hemisphere, even after decades of protection. There are separate populations of Blues in the northern and southern hemispheres. Calves at birth, 7m long.Īppearance At Sea: Blue Whales are generally found in close-knit groups of 3-4 animals which may associate with other such groups for feeding and breeding. Present day individuals are believed to weigh 100 to 120 tons. Such animals were estimated to weigh over 160 tons. Before whaling depleted Blue Whale stocks, individuals of the Antarctic attained lengths of 30.5 m. They attain lengths of 24 to 28 m, females and animals of the southern hemisphere being larger. Size: Adults,These are the largest living animals. The number of ventral grooves as given by different sources varies from 55 to 100. Some animals may have a yellowish or mustard colouration, caused by diatom accumulations. Blue Whales are bluish grey overall, mottled with grey or greyish white. It is located far back on the animal’s tail stock.
The dorsal fin is very small – less than 33 cm high and variable in shape. The flippers are slim and one-seventh the body length. There are two slightly concave regions, above the lungs.
There is one ridge from the blowhole to the tip of the snout. General Description: The body is very broad and the head is U-shaped when seen from above, whilst the tail stock is narrow.